tickle/modules/utils/createCustomElement.mjs

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2023-05-13 15:26:48 +00:00
//@ts-check
const createOptions = () => ({
name: "my-custom-element",
css: ":host{}",
html: "",
ParentClass: HTMLElement,
observedAttributes: /** @type {string[]}*/ ([]),
});
/**
* WIP: minimal API for custom elements. Do not use!
* @typedef {ReturnType<typeof createOptions>} Options
* @param {Partial<Options>} [options]
*/
export const createCustomElement = (options) => {
const {
name,
css,
html,
observedAttributes: attrs,
ParentClass,
} = { ...createOptions(), ...options };
class CustomClass extends ParentClass {
static template = document.createElement("template");
static stylesheet = new CSSStyleSheet();
constructor(){
super()
}
/**
* Registers the custom element. If it was already registered, this is a no-op.
* @param {string} tag
*/
static define(tag = name) {
if (!customElements.get(tag)) {
customElements.define(tag, this);
}
}
static get observedAttributes() {
return attrs;
}
attributeChangedCallback(property, oldValue, newValue) {
if (oldValue === newValue) {
return;
}
this[property] = newValue;
}
/** @type {AbortController|null} */
_abortController = null;
/**
* If no <template> tag is provided in the page, this uses the parent classe's
* template and css to create markup
* Use this in the constructor
*/
_autoCreateShadow(){
if (!this.shadowRoot) {
const { stylesheet, template } =
Object.getPrototypeOf(this).constructor;
this.shadowRoot = this.attachShadow({ mode: "open" });
this.shadowRoot.adoptedStyleSheets = [stylesheet];
this.shadowRoot.replaceChildren(template.content.cloneNode(true));
}
}
_getAbortSignal(){
if(!this._abortController){
this._abortController = new AbortController()
}
return this._abortController.signal
}
/**
* Aborts any event that used the AbortSignal.
* Use this in the `disconnectedCallback` call
*/
_abort(){
this._abortController && this._abortController.abort();
}
}
const x = new CustomClass();
CustomClass.template.innerHTML = html;
CustomClass.stylesheet.replaceSync(css);
Object.defineProperty(CustomClass, "name", { value: name.replace(/-/s,'') });
return CustomClass;
};
export default createCustomElement